Submitted by Raniere Barreto (raniere.barros@ufvjm.edu.br) on 2018-04-13T17:44:56Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wallinson_oliveira_schutte.pdf: 2955879 bytes, checksum: 7d21ec1707fa5cf82b0b96642d27fa03 (MD5) / Rejected by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br), reason: Verificar refer?ncia e keywords. on 2018-04-20T15:00:26Z (GMT) / Submitted by Raniere Barreto (raniere.barros@ufvjm.edu.br) on 2018-05-15T18:16:15Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wallinson_oliveira_schutte.pdf: 2955879 bytes, checksum: 7d21ec1707fa5cf82b0b96642d27fa03 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-05-15T19:38:43Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wallinson_oliveira_schutte.pdf: 2955879 bytes, checksum: 7d21ec1707fa5cf82b0b96642d27fa03 (MD5) / Made available in DSpace on 2018-05-15T19:38:43Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) wallinson_oliveira_schutte.pdf: 2955879 bytes, checksum: 7d21ec1707fa5cf82b0b96642d27fa03 (MD5) Previous issue date: 2017 / O presente estudo prop?e o desenvolvimento de duas ferramentas para se fazer a classifica??o de batimentos card?acos a fim de detectar a Isquemia Card?aca. Uma baseada em propriedades da Distribui??o Normal e Teorema de Bayes e a outra baseada em Redes Neurais Artificiais. Utilizando o banco de dados Long-Term ST Database, foi efetuado um filtro de dados, que foram agrupados pelas seguintes deriva??es: A-S, E-S, A-I, ML2, MV2, ML3, V4 e V5. Por meio dos algoritmos propostos, implementados por interm?dio da Linguagem de Programa??o PHP, p?de-se verificar a deriva??o mais prop?cia a se detectar essa doen?a. Foi poss?vel observar as deriva??es V5 e A-S com melhores resultados utilizando-se o algoritmo h?brido. Na V5, foi obtido Sensibilidade de 100%, Especificidade de 97%, Valor Preditivo Positivo de 95.89% e Valor Preditivo Negativo de 100% e, na A-S, valores de 99.22%, 99.99%, 99.99% e 99.61% para Sensibilidade, Especificidade, Valor Preditivo Positivo e Valor Preditivo Negativo. O algoritmo de Redes Neurais Artificiais apresentou o melhor resultado para deriva??o A-S com 99.98%, 100%, 100% e 99.99% para Sensibilidade, Especificidade, Valor Preditivo Positivo e Valor Preditivo Negativo respectivamente. Tamb?m foi calculado o intervalo de confian?a para propor??es populacionais com 95% de confian?a, a fim de se estabelecer n?veis de precis?o das bases utilizadas. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Tecnologia, Sa?de e Sociedade, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The present study proposes the development of two tools to classify heart beats in order to detect cardiac ischemia. One based on properties of Normal Distribution and Bayes' Theorem and the other based on Artificial Neural Networks. Using the Long-Term ST Database, a data filter was performed, which was grouped by the following derivations: A-S, E-S, A-I, ML2, MV2, ML3 and V4, V5. By means of the algorithms proposed, implemented through the PHP Programming Language, we could verify the most favorable derivation to detect this disease. It was possible to observe the V5 and A-S leads with better results using the hybrid algorithm. In V5, 100% sensitivity, 97% specificity, 95.89% positive predictive value and 100% negative predictive value were obtained, and in A-S, values of 99.22%, 99.99%, 99.99% and 99.61% for sensitivity, specificity, positive predictive value, and negative predictive value. The algorithm of Artificial Neural Networks presented the best result for A-S derivation with 99.98%, 100%, 100% and 99.99% for sensitivity, specificity, positive predictive value and negative predictive value respectively. We also calculated the confidence interval for population proportions with 95% confidence in order to establish precision levels of the bases used. / El presente estudio propone el desarrollo de dos herramientas para la clasificaci?n de los latidos del coraz?n con el fin de detectar la isquemia card?aca. Uno basado en las propiedades de la Distribuci?n Normal y el Teorema de Bayes y el otro basado en las Redes Neuronales Artificiales. Utilizando la base de datos Long-Term ST Database, se llev? a cabo un filtro de datos, que fueron agrupados seg?n las siguientes derivaciones: a-S, E, S, A-I, ML2, MV2, ML3, V4 y V5. Por medio de los algoritmos propuestos, implementado a trav?s del lenguaje de programaci?n PHP, pudimos comprobar la derivaci?n m?s favorable para detectar esta enfermedad. Fue posible observar las derivaciones V5 y A-S con mejores resultados utilizando el algoritmo h?brido. En V5 se obtuvo una sensibilidad del 100%, uma especificidad del 97%, 95.89% de valor predictivo positivo y 100% de valor predictivo negativo y en A-S, valores de 99.22%, 99.99%, 99.99% y 99.61% para la sensibilidad, especificidad, valor predictivo positivo, y valor predictivo negativo respectivamente. El algoritmo de Redes Neuronales Artificiales present? el mejor resultado para la derivaci?n A-S con 99.98%, 100%, 100% y 99.99% para la sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo, respectivamente. Tambi?n fue calculado el intervalo de confianza para proporciones de las poblaciones con 95% de confianza con el fin de establecer los niveles de confianza precisi?n de las bases utilizadas

Made available in DSpace on 2014-12-17T13:53:23Z (GMT). No. of bitstreams: 1 GeorgeAOG.pdf: 5538923 bytes, checksum: 36d483843a1b6d01c32a0cf34fd0f3e3 (MD5) Previous issue date: 2009-09-25 / This study examines the complex hotel buyer decision process in front of the tourism distribution channels. Its objective is to describe the influence level of the tourism marketing intermediaries, mainly the travel agents and tour operators, over the hotel decision process by the buyer-tourist. The data collection process was done trough a survey with three hundred brazilian tourists hosted in nineteen hotels of Natal, capital of Rio Grande do Norte, Brazil. The data analysis was done using some multivariate statistic techniques as correlation analysis, multiple regression analysis, factor analysis and multiple discriminant analysis. The research characterizes the hotel services consumers profile and his trip, and identifying the distribution channels used by them. Furthermore, the research verifies the intermediaries influence exercised over hotel buyer decision process, looking for identify causality relations between the influence level and the buyer profile. Verifies that information about hotels available on internet reduces the probability that this influence can be practiced; however it was possible identifying those consumers considers this information complementary and non-substitutes than the information from intermediaries. The characteristics of the data do not allow indentifying the factors that constraint the intermediaries influence neither identifying discriminant functions of the specific distribution channel choice by consumers. The study concludes that consumers don t agree in have been influenced by intermediaries or don t know if they have, still considering important to consult them and internet doesn t substitute their function as information source / O presente estudo trata do complexo processo de decis?o do consumidor de servi?os de hospedagem frente aos canais de distribui??o do turismo. Tem como objetivo descrever o n?vel de influ?ncia dos intermedi?rios de distribui??o de produtos tur?sticos, principalmente das ag?ncias de viagens e das operadoras tur?sticas, exercida sobre o processo de escolha do meio de hospedagem pelo consumidor. A coleta de dados se deu atrav?s da aplica??o de trezentos question?rios em turistas brasileiros, hospedados em dezenove hot?is de Natal, capital do Rio Grande do Norte. A an?lise dos dados desenvolveu-se atrav?s de ferramentas estat?sticas multivariadas como a correla??o entre vari?veis, a regress?o linear m?ltipla, a an?lise fatorial e a an?lise discriminante. A pesquisa caracteriza o perfil dos consumidores de servi?os de hospedagem e sua viagem, al?m de identificar os canais de distribui??o por eles utilizados. Verifica a influ?ncia exercida pelos intermedi?rios sobre os consumidores na escolha do meio de hospedagem, buscando identificar rela??es causais entre esta influ?ncia e as caracter?sticas do consumidor. Constata que as informa??es sobre os meios de hospedagem dispon?veis na internet reduzem a probabilidade de que esta influ?ncia seja exercida, entretanto identifica que os consumidores consideram estas informa??es complementares e n?o substitutas ?quelas fornecidas pelos intermedi?rios. As caracter?sticas dos dados obtidos n?o permitem a identifica??o de fatores que condicionam a influ?ncia dos intermedi?rios, nem a identifica??o de fun??es que discriminem a escolha do consumidor por determinado canal de distribui??o. Conclui que o consumidor n?o concorda em ter sido influenciado pelo intermedi?rio ou n?o tem consci?ncia de que o foi, mesmo considerando que ? importante consult?-los e que a internet n?o substitui sua fun??o de fonte de informa??es

Made available in DSpace on 2014-12-17T14:02:01Z (GMT). No. of bitstreams: 1 TiegoLAC_DISSERT.pdf: 2534713 bytes, checksum: 03b88ab9e5892a0fca8b5b5ff0512692 (MD5) Previous issue date: 2011-07-09 / The species Dasyatis marianae inhabits coastal areas associated with coral reefs, considered endemic to the northeast of Brazil, occurring from the State of Maranh?o to the south of Bahia. Specimens of this species are commonly sighted by divers and fishermen in the area of Maracaja? reefs, a complex reef that is part of the Environmental Protection Area of Coral Reefs (EPACR), which was developed in this study about the ecology and biology of the D. marianae, in order to characterize aspects of population structure in the area of the reef complex of Parracho de Maracaja?. We analyzed 120 specimens caught by artisanal fishing site of the size, weight, sex, stage of maturity and stomach contents. Most subjects were adult males (1.7:1) and was more abundant for rays with lengths between 25 and 29cm of LD, where females reach larger sizes, a feature common to other rays. The largest specimens were captured in the area of seagrass, which is preferred for the species. The distribution of species in the area showed an ontogenetic and sexual segregation, where the youthful occur near the beach, which is a likely area for nursery and growth of the adult females prevail in the seagrass, which apparently has a high prey availability, and Adult males are more distant, a higher proportion occurring in outlying areas, suggesting a habit more exploratory than the females. The evaluation of the reproductive system indicated 3 reproductive cycles per year, one young per pregnancy, and showed that the mature males were smaller than females. The cubs of D. marianae size at birth 12 to 15cm LD. As for diet, the species was characterized as carnivorous crustacean specialist. The performance of visual censuses in different localities allowed to evaluate the density of D. marianae in different environments of the complex. The species occurs in greater numbers in seagrass, environment very important for the conservation of the species. 100 individuals of D. marianae marked in reef complex area enrolled in a recapture rate of 3%. Some behavioral aspects were evaluated, as diurnal pattern of activity, interaction with cleaning and fish Pomacanthus paru followers as Lutjanus analis and Carangoides bartholomaei. Overall, much of the information obtained should be used for management of the species / A esp?cie Dasyatis marianae habita ?reas costeiras associadas a recifes de corais, sendo considerada end?mica para o nordeste do Brasil, ocorrendo desde o Estado do Maranh?o at? o sul da Bahia. Exemplares da esp?cie s?o comumente avistados por mergulhadores e pescadores na ?rea do Parracho de Maracaja?, um complexo recifal que faz parte da ?rea de Prote??o Ambiental dos Recifes de Corais (APARC), onde foi desenvolvido o presente estudo, acerca da ecologia e biologia da D. marianae, com a finalidade de caracterizar aspectos da estrutura populacional na ?rea do complexo recifal do Parracho de Maracaja?. Foram analisados 120 exemplares capturados pela pesca artesanal local quanto ao tamanho, peso, sexo, est?gio de matura??o e conte?do estomacal. A maioria dos indiv?duos foram machos adultos (1,7:1) e a maior abund?ncia foi para raias com tamanhos entre 25 e 29cm de LD, onde as f?meas atingem maiores os tamanhos, caracter?stica comum a outras raias. Os exemplares de maior porte foram capturados na ?rea de faner?gamas, que ? preferencial para a esp?cie. A distribui??o da esp?cie na ?rea apresentou uma segrega??o sexual e ontogen?tica, onde os juvenis ocorrem pr?ximo ? praia, que ? uma prov?vel ?rea de ber??rio e crescimento destes, as f?meas adultas prevalecem nas faner?gamas, que aparentemente tem uma elevada disponibilidade de presas, e os machos adultos se distanciam mais, ocorrendo numa maior propor??o nas ?reas mais afastadas, sugerindo um h?bito mais explorat?rio quando comparado ?s f?meas. A avalia??o do sistema reprodutivo apontou 3 ciclos reprodutivos anuais, um filhote por gesta??o e mostrou que os machos maturam com menor tamanho que as f?meas. Os filhotes de D. marianae nascem com tamanho de 12 a 15cm de LD. Quanto ? dieta, a esp?cie foi caracterizada como carn?vora carcinof?gica especialista. A realiza??o de censos visuais em diferentes localidades permitiu avaliar a densidade de D. marianae nos ambientes distintos do complexo. A esp?cie ocorre em maior n?mero nas faner?gamas, ambiente muito importante para a conserva??o da esp?cie. De 100 indiv?duos de D. marianae marcados na ?rea do complexo recifal registrou-se uma taxa de recaptura de 3%. Alguns aspectos comportamentais foram avaliados, como padr?o de atividade diurna, intera??o de limpeza com Pomacanthus paru e peixes seguidores como Lutjanus analis e Carangoides bartholomaei. De forma geral, muitas das informa??es obtidas dever?o ser usadas para o manejo adequado da esp?cie

Made available in DSpace on 2015-03-13T17:08:15Z (GMT). No. of bitstreams: 1 MarciaGS_ ate_Cap4.pdf: 2549651 bytes, checksum: 6eb717ac0ed84f3e72d899abd57a073f (MD5) Previous issue date: 1999-08-24 / Petr?leo Brasileiro SA - PETROBRAS / This dissertation deals with the characterization, distribution and provenience of heavy minerals along the Piranhas-A?u River, from the City of Parelhas (Serid? River) to your mouth at the City of Macau-RN. Many heavy minerals species were recorded in this study: clinoamphibole, epidote (including zoisite), garnet, sillimanite, tourmaline, staurolite, andalusite, zircon, rutile, augite, ilmenite, hematite and magnetite. Major transparent minerals, those forming more than 5% of some assemblages, are hornblende, epidote, tourmaline, staurolite and zircon. Predominant opaque mineral is ilmenite. Six assemblages were identified along the river: (i) Garnet-hornblende-tourmaline with sillimanite, when cutting rocks of the Serid? Formation; (ii) Hornblende-garnet-zircon, when crossing rocks of the Caic? gnaisse-migmatitic Complex; (iii) Hornblende-zircon-epidote-staurolite, when draining rocks of the Jucurutu Formation; (iv) Hornblende-zircon-epidote, when cutting rocks of the A?u Formation; (v) Hornblende-zircon-staurolite, on the lowermost A?u River, when crossing limestones of the Janda?ra Formation and (vi) Zircon-tourmaline-staurolite in the A?u River mouth (Cenozoic rocks) where coastal process dominate. Mineral ratios that reflect differences in grain shape, density, and selective chemical decomposition were used in an attempt to isolate the effects of source and process as controls of mineral variability. Reworking of the sediments was regionally effective in selective sorting; the more equant minerals (e.g. epidote) and heavier minerals (e.g. opaques) had a higher probability of being selected for permanent deposition during reworking. The processes of selective decomposition stand out at the river mouth. A priori knowledge of provenance, associated with the assemblage distribution and effects of process were utilized to the interpretations, that points to the follow provenances: hornblende comes from micashists of the Serid? Formation, orthognaisses and amphibolites of the Caico Complex, paragnaisses and paranphibolites of the Jucurutu Formation and granites intrusions; epidote comes from paragnaisses and calciosilicatics of the Jucurutu Formation, granites intrusions (?-Npy3al/ca and ?-Npy3mz, gravels deposits and A?u Formation; Andalusite and staurolite come from the Serid? Formation; Sillimanite, tourmaline and garnet come from micashists of the Serid? Formation, as well as from quartzites of the Equador Formation; Zircon comes from Precambrian rocks (pink and prismatic zircon) and from sediments of several cycles (round zircon); Opaques come from all rocks cutted for the Piranhas-A?u River; Rutile comes from metamorphic rocks, in general; Augite comes from the Cear?-Mirim, Serra do Cu? and Macau volcanisms. The texture of gravels deposits reveals a sediment transport mechanisms by traction-current processes, together with a diagenetic clay matrix suggests a hot-humid environments for deposition. The presence of unstable heavy minerals assemblages, as well as pebbles of different composition and degrees of rounding and esfericity, indicate more than one source. The occurrence of calcio/alkaline granites suites, in areas closed to the gravel deposits, suggests that these intrusions are the main source of sediments. This could explain for instance, the significant amounts of epidote and presence of unstable heavy minerals (e.g. hornblende). The analyses of heavy minerals also show significante variability between the modern (Piranhas-A?u) and ancestral (A?u Formation) river sediments. In general, these variations reflect relatively higher unstable and lower stable heavy minerals contents of the modern Piranhas-A?u sediments. The absence of significant compositional differences probably reflects uniform weathering conditions / This dissertation deals with the characterization, distribution and provenience of heavy minerals along the Piranhas-A?u River, from the City of Parelhas (Serid? River) to your mouth at the City of Macau-RN. Many heavy minerals species were recorded in this study: clinoamphibole, epidote (including zoisite), garnet, sillimanite, tourmaline, staurolite, andalusite, zircon, rutile, augite, ilmenite, hematite and magnetite. Major transparent minerals, those forming more than 5% of some assemblages, are hornblende, epidote, tourmaline, staurolite and zircon. Predominant opaque mineral is ilmenite. Six assemblages were identified along the river: (i) Garnet-hornblende-tourmaline with sillimanite, when cutting rocks of the Serid? Formation; (ii) Hornblende-garnet-zircon, when crossing rocks of the Caic? gnaisse-migmatitic Complex; (iii) Hornblende-zircon-epidote-staurolite, when draining rocks of the Jucurutu Formation; (iv) Hornblende-zircon-epidote, when cutting rocks of the A?u Formation; (v) Hornblende-zircon-staurolite, on the lowermost A?u River, when crossing limestones of the Janda?ra Formation and (vi) Zircon-tourmaline-staurolite in the A?u River mouth (Cenozoic rocks) where coastal process dominate. Mineral ratios that reflect differences in grain shape, density, and selective chemical decomposition were used in an attempt to isolate the effects of source and process as controls of mineral variability. Reworking of the sediments was regionally effective in selective sorting; the more equant minerals (e.g. epidote) and heavier minerals (e.g. opaques) had a higher probability of being selected for permanent deposition during reworking. The processes of selective decomposition stand out at the river mouth. A priori knowledge of provenance, associated with the assemblage distribution and effects of process were utilized to the interpretations, that points to the follow provenances: hornblende comes from micashists of the Serid? Formation, orthognaisses and amphibolites of the Caico Complex, paragnaisses and paranphibolites of the Jucurutu Formation and granites intrusions; epidote comes from paragnaisses and calciosilicatics of the Jucurutu Formation, granites intrusions (?-Npy3al/ca and ?-Npy3mz, gravels deposits and A?u Formation; Andalusite and staurolite come from the Serid? Formation; Sillimanite, tourmaline and garnet come from micashists of the Serid? Formation, as well as from quartzites of the Equador Formation; Zircon comes from Precambrian rocks (pink and prismatic zircon) and from sediments of several cycles (round zircon); Opaques come from all rocks cutted for the Piranhas-A?u River; Rutile comes from metamorphic rocks, in general; Augite comes from the Cear?-Mirim, Serra do Cu? and Macau volcanisms. The texture of gravels deposits reveals a sediment transport mechanisms by traction-current processes, together with a diagenetic clay matrix suggests a hot-humid environments for deposition. The presence of unstable heavy minerals assemblages, as well as pebbles of different composition and degrees of rounding and esfericity, indicate more than one source. The occurrence of calcio/alkaline granites suites, in areas closed to the gravel deposits, suggests that these intrusions are the main source of sediments. This could explain for instance, the significant amounts of epidote and presence of unstable heavy minerals (e.g. hornblende). The analyses of heavy minerals also show significante variability between the modern (Piranhas-A?u) and ancestral (A?u Formation) river sediments. In general, these variations reflect relatively higher unstable and lower stable heavy minerals contents of the modern Piranhas-A?u sediments. The absence of significant compositional differences probably reflects uniform weathering conditions

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-02T22:57:03Z No. of bitstreams: 1 YuriShalomDeFreitasBezerra_DISSERT.pdf: 1870636 bytes, checksum: fa87a782197886fe563d90143a5c4a3a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-09T20:15:23Z (GMT) No. of bitstreams: 1 YuriShalomDeFreitasBezerra_DISSERT.pdf: 1870636 bytes, checksum: fa87a782197886fe563d90143a5c4a3a (MD5) / Made available in DSpace on 2015-12-09T20:15:23Z (GMT). No. of bitstreams: 1 YuriShalomDeFreitasBezerra_DISSERT.pdf: 1870636 bytes, checksum: fa87a782197886fe563d90143a5c4a3a (MD5) Previous issue date: 2014-08-30 / O m?todo de Monte Carlo ? preciso e, quando comparado com outras t?cnicas num?ricas, ? de relativamente f?cil implementa??o para a solu??o de problemas envolvendo geometrias complexas e espalhamento anisotr?pico da radia??o. Al?m disso, diferentemente do que ocorre para a maioria das t?cnicas num?ricas, cujo tempo necess?rio para a execu??o de simula??es tende a crescer exponencialmente ? medida que a complexidade do problema aumenta, no Monte Carlo, o aumento no tempo computacional tende a ser linear. Ainda assim, as solu??es em Monte Carlo s?o computacionalmente pesadas para a solu??o da maioria dos problemas de interesse. O modelo dos Pacotes de Energia Multiespectrais permite a redu??o dos tempos computacionais associados ?s solu??es atrav?s do m?todo de Monte Carlo. O modelo ? aqui analisado para aplica??es em meios constitu?dos por esp?cies n?o-participantes e vapor d??gua, que ? um importante emissor de radia??o formado na combust?o de hidrocarbonetos. Aspectos relacionados ? otimiza??o dos tempos computacionais s?o investigados e solu??es obtidas com o modelo s?o comparadas com solu??es linha-por-linha benchmark. / The Monte Carlo method is accurate and is relatively simple to implement for the solution of problems involving complex geometries and anisotropic scattering of radiation as compared with other numerical techniques. In addition, differently of what happens for most of numerical techniques, for which the associated simulations computational time tends to increase exponentially with the complexity of the problems, in the Monte Carlo the increase of the computational time tends to be linear. Nevertheless, the Monte Carlo solution is highly computer time consuming for most of the interest problems. The Multispectral Energy Bundle model allows the reduction of the computational time associated to the Monte Carlo solution. The referred model is here analyzed for applications in media constituted for nonparticipating species and water vapor, which is an important emitting species formed during the combustion of hydrocarbon fuels. Aspects related to computer time optimization are investigated the model solutions are compared with benchmark line-by-line solutions

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T19:01:21Z No. of bitstreams: 1 RegivaldoDeOliveiraFalcao_DISSERT.pdf: 2070708 bytes, checksum: d2030edd45895ed4d631e7484ff6f7c1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T21:49:26Z (GMT) No. of bitstreams: 1 RegivaldoDeOliveiraFalcao_DISSERT.pdf: 2070708 bytes, checksum: d2030edd45895ed4d631e7484ff6f7c1 (MD5) / Made available in DSpace on 2016-01-28T21:49:26Z (GMT). No. of bitstreams: 1 RegivaldoDeOliveiraFalcao_DISSERT.pdf: 2070708 bytes, checksum: d2030edd45895ed4d631e7484ff6f7c1 (MD5) Previous issue date: 2014-12-19 / O presente trabalho teve como objeto de estudo um sistema de gera??o de vapor, distribui??o de vapor e retorno de condensado de uma planta t?xtil localizada no Rio Grande do Norte. O trabalho teve como base os seguintes objetivos: Conhecer o uso do vapor saturado de ?gua nos processos de tinturaria e acabamento em uma planta t?xtil; Estudar os diversos aspectos de um sistema de distribui??o de vapor, para identificar as formas em que ocorrem perdas de energia; Obter informa??es quantitativas das principais perdas de vapor no sistema de gera??o e distribui??o de vapor e mensurar as perdas, ?gua e vapor, do sistema; Utilizar o vapor flash como forma de redu??o de custo. Para isso fez-se uso da apura??o dos ganhos financeiros apresentados nas suas respectivas melhorias. Como base de dados para o desenvolvimento do trabalho utilizou-se registros de processos industriais, dados dos sistemas de utilidades, dados de an?lises de laborat?rio e de analisadores em linha, abrangendo o per?odo de 2013. Usando-se princ?pios consagrados das leis de conserva??o de massa e energia, o tratamento desses dados mostrou que as perdas de ?gua e energia no sistema de vapor s?o expressivas e que os ganhos ambientais e econ?micos que poder?o ser obtidos com a??es de melhoria s?o bastante significativas. Tomando como base os dados e resultados obtidos sugiro que os estudos futuros deem continuidade a abordagem sobre sistemas de gera??o de vapor, distribui??o e, principalmente, retorno de condensado / This study focused object a steam generation system, steam distribution and condensate return a textile plant located in Rio Grande do Norte. The work was based on the following objectives: Knowing the use of saturated water vapor in the dyeing and finishing processes in a textile plant; To study the various aspects of a steam distribution system to identify the ways in which energy losses occur; Obtain quantitative information of the main loss in steam generation system and steam distribution and to measure the losses, water and steam system; Using the flash steam as a means of cost reduction. For it was made use of the calculation of financial gains made in their respective improvements. As a database for the development of working registers are used in industrial processes, data from utility systems, laboratory data analysis and on-line analyzers, covering the period 2013. Using the principles set conservation laws mass and energy, those data showed that the loss of water and energy in the steam system are significant and that the environmental and economic gains to be obtained with improvement actions are quite significant. Based on the data and results suggest that future studies deem the continuity approach to steam generation systems, distribution and mainly condensate return.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-08T22:40:13Z No. of bitstreams: 1 ThatianaCunhaNavarroDeSouza_TESE.pdf: 4253732 bytes, checksum: b88b33669e4903291d2e3da03d76f832 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-11T22:01:06Z (GMT) No. of bitstreams: 1 ThatianaCunhaNavarroDeSouza_TESE.pdf: 4253732 bytes, checksum: b88b33669e4903291d2e3da03d76f832 (MD5) / Made available in DSpace on 2016-04-11T22:01:06Z (GMT). No. of bitstreams: 1 ThatianaCunhaNavarroDeSouza_TESE.pdf: 4253732 bytes, checksum: b88b33669e4903291d2e3da03d76f832 (MD5) Previous issue date: 2015-03-13 / Um importante problema enfrentado pela ind?stria petrol?fera ? distribuir v?rios produtos derivados de petr?leo atrav?s de polidutos. Tal distribui??o ? feita atrav?s de uma rede composta por refinarias (n?s fonte), parques de armazenagem (n?s intermedi?rios) e terminais (n?s de demanda), interligados por um conjunto de polidutos que transportam petr?leo e derivados entre ?reas adjacentes. Restri??es relativas a limites de armazenamento, tempo de entrega, disponibilidade das fontes, limites de envio e recebimento, entre outras, t?m de ser satisfeitas. Alguns pesquisadores lidam com este problema sob o ponto de vista discreto onde o fluxo na rede ? visto como o envio de bateladas. Geralmente, n?o existem dispositivos de separa??o entre bateladas de produtos diferentes e as perdas devidas ? interface podem ser significativas. Minimizar o tempo de entrega ? um objetivo usual dos engenheiros durante a programa??o do envio de produtos em redes de polidutos. No entanto, os custos devidos ?s perdas geradas nas interfaces n?o podem ser desconsiderados. O custo do envio dos produtos tamb?m depende das despesas de bombeamento as quais s?o, em grande parte, devidas ao custo da energia el?trica. Uma vez que a tarifa industrial de energia el?trica varia ao longo do dia, o bombeamento em diferentes per?odos ter?o diferentes custos. Este trabalho apresenta uma investiga??o experimental de m?todos computacionais desenvolvidos para lidar com o problema do envio de bateladas de derivados de petr?leo considerando a minimiza??o simult?nea de tr?s fun??es objetivo: tempo de entrega, perdas devidas ?s interfaces e custo de energia el?trica. Tal problema ? NP- ?rduo e ser? abordado atrav?s de algoritmos evolucion?rios h?bridos. As hibridiza??es t?m como foco principal os Algoritmos Transgen?ticos e arquiteturas cl?ssicas de algoritmos evolucion?rios multi-objetivo como MOEA/D, NSGA2 e SPEA2. Tr?s arquiteturas denominadas MOTA/D, NSTA e SPETA, s?o aplicadas ao problema. ? apresentado um estudo experimental dos algoritmos propostos onde ? utilizado um conjunto de trinta casos teste. Para analisar os resultados obtidos com os algoritmos s?o empregados indicadores de qualidade Pareto concordantes e testes estat?sticos n?o param?tricos. / An important problem faced by the oil industry is to distribute multiple oil products through pipelines. Distribution is done in a network composed of refineries (source nodes), storage parks (intermediate nodes), and terminals (demand nodes) interconnected by a set of pipelines transporting oil and derivatives between adjacent areas. Constraints related to storage limits, delivery time, sources availability, sending and receiving limits, among others, must be satisfied. Some researchers deal with this problem under a discrete viewpoint in which the flow in the network is seen as batches sending. Usually, there is no separation device between batches of different products and the losses due to interfaces may be significant. Minimizing delivery time is a typical objective adopted by engineers when scheduling products sending in pipeline networks. However, costs incurred due to losses in interfaces cannot be disregarded. The cost also depends on pumping expenses, which are mostly due to the electricity cost. Since industrial electricity tariff varies over the day, pumping at different time periods have different cost. This work presents an experimental investigation of computational methods designed to deal with the problem of distributing oil derivatives in networks considering three minimization objectives simultaneously: delivery time, losses due to interfaces and electricity cost. The problem is NP-hard and is addressed with hybrid evolutionary algorithms. Hybridizations are mainly focused on Transgenetic Algorithms and classical multi-objective evolutionary algorithm architectures such as MOEA/D, NSGA2 and SPEA2. Three architectures named MOTA/D, NSTA and SPETA are applied to the problem. An experimental study compares the algorithms on thirty test cases. To analyse the results obtained with the algorithms Pareto-compliant quality indicators are used and the significance of the results evaluated with non-parametric statistical tests.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-25T21:18:31Z No. of bitstreams: 1 LuisFilipeAzevedoDeOliveira_DISSERT.pdf: 2758518 bytes, checksum: 7f5afec1f5d1f9f925d4aac95380ba09 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-27T19:58:21Z (GMT) No. of bitstreams: 1 LuisFilipeAzevedoDeOliveira_DISSERT.pdf: 2758518 bytes, checksum: 7f5afec1f5d1f9f925d4aac95380ba09 (MD5) / Made available in DSpace on 2016-04-27T19:58:21Z (GMT). No. of bitstreams: 1 LuisFilipeAzevedoDeOliveira_DISSERT.pdf: 2758518 bytes, checksum: 7f5afec1f5d1f9f925d4aac95380ba09 (MD5) Previous issue date: 2014-02-24 / No Brasil, o agente regulador do setor de energia el?trica ? representado pela Ag?ncia Nacional de Energia El?trica. A revis?o das tarifas tem sido uma das suas principais atribui??es, ao estabelecer uma pr?tica tarif?ria em um n?vel compat?vel com a cobertura dos custos operacionais eficientes e a remunera??o adequada dos investimentos realizados pelas distribuidoras. As mudan?as nos procedimentos adotados pelo agente regulador para redefini??o dos custos eficientes, bem como os diversos estudos encontrados na literatura sobre os procedimentos utilizados na regula??o desse segmento denotam o desafio enfrentado sobre qual a melhor estrat?gia metodol?gica a ser empregada. Nesse contexto, esta pesquisa tem como objetivo propor um modelo para avalia??o de benchmarking, aplicado ao sistema de regula??o nacional no estabelecimento dos custos operacionais eficientes das concession?rias de distribui??o de energia el?trica. O modelo ? formulado para promover o desenvolvimento do mercado de energia el?trica, associado com pol?ticas governamentais e em benef?cio da sociedade. Para conduzir esta pesquisa, adota-se uma integra??o do modelo de An?lise Envolt?ria de Dados (DEA) com a An?lise de Fronteira Estoc?stica (SFA), em um procedimento que estabelece tr?s est?gios para corrigir a efici?ncia em termos dos efeitos ex?genos: (i) avalia??o por meio de DEA para mensurar as folgas nos custos operacionais das distribuidoras, em que as vari?veis ex?genas s?o omitidas; (ii) as folgas calculadas no primeiro est?gio s?o regredidas sobre um conjunto de vari?veis ambientais, por meio de SFA e os custos operacionais s?o corrigidos para contabilizar o impacto dos efeitos ambientais e o ru?do estat?stico; e, (iii) reavalia??o do desempenho das concession?rias de distribui??o de energia el?trica, respaldado pelo uso de DEA. A partir dessa metodologia foi poss?vel obter- uma avalia??o do desempenho exclusivamente expresso em termos de efici?ncia de gest?o, nos quais s?o controlados pelos efeitos do meio ambiente operacional e do ru?do estat?stico. A metodologia em tr?s est?gios alcan?ou o principal objetivo, ao nivelar os custos das concession?rias em termos do efeito ex?geno e aleat?rio, tornando o desempenho das concession?rias mais homog?neos. / In Brazil, the National Agency of Electric Energy (ANEEL) represents the energy regulator. The rates review have been one of its main tasks, which establish a pricing practice at a level to cover the efficient operating costs and also the appropriate return of the distributors investments. The changes in the procedures to redefine the efficient costs and the several studies on the methodologies employed to regulate this segment denote the challenge faced by regulators about the best methodological strategy to be employed. In this context, this research aims to propose a benchmarking evaluation applied to the national regulation system in the establishment of efficient operating costs of electricity distribution utilities. The model is formulated to promote the electricity market development, partnering with government policies ant to society benefit. To conduct this research, an integration of Data Envelopment Analysis (DEA) with the Stochastic Frontier Analysis (SFA) is adopted in a three stages procedure to correct the efficiency in terms of environmental effects: (i) evaluation by means of DEA to measure operating costs slacks of the utilities, in which environmental variables are omitted; (ii) The slacks calculated in the first stage are regressed on a set of environmental variables by means of SFA and operating costs are adjusted to account the environmental impact and statistical noise effects; and, (iii) reassess the performance of the electric power distribution utilities by means of DEA. Based on this methodology it is possible to obtain a performance evaluation exclusively expressed in terms of management efficiency, in which the operating environment and statistical noise effects are controlled.

Made available in DSpace on 2014-12-17T14:55:01Z (GMT). No. of bitstreams: 1 MarcosADA.pdf: 1444489 bytes, checksum: 289536fadcf88cdfafb2eefa6b4f2ac4 (MD5) Previous issue date: 2003-12-29 / Most algorithms for state estimation based on the classical model are just adequate for use in transmission networks. Few algorithms were developed specifically for distribution systems, probably because of the little amount of data available in real time. Most overhead feeders possess just current and voltage measurements at the middle voltage bus-bar at the substation. In this way, classical algorithms are of difficult implementation, even considering off-line acquired data as pseudo-measurements. However, the necessity of automating the operation of distribution networks, mainly in regard to the selectivity of protection systems, as well to implement possibilities of load transfer maneuvers, is changing the network planning policy. In this way, some equipments incorporating telemetry and command modules have been installed in order to improve operational features, and so increasing the amount of measurement data available in real-time in the System Operation Center (SOC). This encourages the development of a state estimator model, involving real-time information and pseudo-measurements of loads, that are built from typical power factors and utilization factors (demand factors) of distribution transformers. This work reports about the development of a new state estimation method, specific for radial distribution systems. The main algorithm of the method is based on the power summation load flow. The estimation is carried out piecewise, section by section of the feeder, going from the substation to the terminal nodes. For each section, a measurement model is built, resulting in a nonlinear overdetermined equations set, whose solution is achieved by the Gaussian normal equation. The estimated variables of a section are used as pseudo-measurements for the next section. In general, a measurement set for a generic section consists of pseudo-measurements of power flows and nodal voltages obtained from the previous section or measurements in real-time, if they exist -, besides pseudomeasurements of injected powers for the power summations, whose functions are the load flow equations, assuming that the network can be represented by its single-phase equivalent. The great advantage of the algorithm is its simplicity and low computational effort. Moreover, the algorithm is very efficient, in regard to the accuracy of the estimated values. Besides the power summation state estimator, this work shows how other algorithms could be adapted to provide state estimation of middle voltage substations and networks, namely Schweppes method and an algorithm based on current proportionality, that is usually adopted for network planning tasks. Both estimators were implemented not only as alternatives for the proposed method, but also looking for getting results that give support for its validation. Once in most cases no power measurement is performed at beginning of the feeder and this is required for implementing the power summation estimations method, a new algorithm for estimating the network variables at the middle voltage bus-bar was also developed / A grande maioria dos algoritmos de estima??o de estado, que usa o modelo cl?ssico, se destina ? aplica??o em sistemas de transmiss?o. H? poucos algoritmos para sistemas de distribui??o. Isto se deve em parte, a pequena quantidade de dados de medi??o dispon?veis em tempo real. A maioria dos alimentadores s? disp?e de medi??o de corrente na sa?da do barramento de m?dia tens?o da subesta??o. Dessa forma, a aplica??o de algoritmos tradicionais de estima??o de estado para a supervis?o de alimentadores pode ser inadequada, mesmo considerando dados obtidos off-line atrav?s de pseudomedi??es. Entretanto, a necessidade de automatiza??o da opera??o dos sistemas de distribui??o, principalmente no que diz respeito ? seletividade quando da presen?a de defeitos, fez surgir alguns equipamentos telecomandados, que incorporam m?dulos de telemedi??o de algumas grandezas da rede, que podem ser transmitidas em tempo real para o centro de opera??o do sistema COS. Isso permite o desenvolvimento de um novo modelo de estimador de estado, envolvendo medidas reais e pseudomedidas de cargas, que s?o constru?das a partir da defini??o de fatores de pot?ncia e de utiliza??o t?picos de sistemas de distribui??o. O presente trabalho trata do desenvolvimento de um novo modelo de estimador de estado voltado para sistemas de distribui??o, particularmente, alimentadores radiais. Baseia-se no algoritmo do fluxo de carga soma de pot?ncias. Da? o nome estimador de estado de soma de pot?ncias. O m?todo faz a estima??o de alimentador por se??o, partindo da subesta??o para os ramais. Para cada se??o ? constru?do o modelo de medi??o. Isto resulta em sistemas de equa??es n?o-lineares, sobre determinados, que requerem uma solu??o iterativa. Obt?m-se essa solu??o atrav?s do m?todo dos m?nimos quadrados ponderados via equa??o normal de Gauss. As grandezas estimadas em uma se??o s?o usadas como pseudomedidas para estimar a se??o subseq?ente. O conjunto de medi??o de cada se??o ? constitu?do por pseudomedidas ou medidas de fluxos de pot?ncia nos trechos e tens?es nodais, em tempo real, e por pseudomedidas de inje??es de pot?ncias nos n?s. As pseudomedidas de inje??es de pot?ncia s?o constru?das a partir das equa??es cl?ssicas de pot?ncias injetadas, usadas no estudo de fluxo de carga. Assume-se ainda, que o sistema trif?sico pode ser representado por seu equivalente monof?sico. A grande vantagem do algoritmo est? na simplicidade e rapidez do programa computacional que o implementa. Al?m disso, ? muito eficiente no que diz respeito ? exatid?o das grandezas estimadas. Al?m do estimador soma de pot?ncias, este trabalho mostra como outros algoritmos poderiam ser adaptados para prover estima??o de estado de subesta??es e circuitos de m?dia tens?o, isto ?, o m?todo de Schweppe e um algoritmo baseado em proporcionalidade de corrente, que normalmente ? usado em estudos de planejamento de redes. Ambos os estimadores foram implementados n?o somente como alternativas para o m?todo proposto, mas tamb?m procurando obter resultados para servir de suporte para sua valida??o. Uma vez que na maioria dos casos n?o h? medi??o de pot?ncias na sa?da para o alimentador e esta ? requerida para implementa??o do m?todo da soma de pot?ncias, um novo algoritmo para estimar as grandezas de rede em barra de m?dia tens?o foi tamb?m desenvolvido

Made available in DSpace on 2014-12-17T14:55:01Z (GMT). No. of bitstreams: 1 MaxCPF.pdf: 2755624 bytes, checksum: a03e472afc07077b6c8f8b043b88366b (MD5) Previous issue date: 2005-10-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developping the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. Its important to point out that, in spite of the loads being normally connected to the transformers secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity / A utiliza??o de c?lculos de fluxo de carga para an?lise de sistemas de transmiss?o de energia el?trica ? algo que vem sendo feito desde da d?cada de 50. Portanto, sabendo-se as caracter?sticas f?sicas do sistema, como os tipos de cabos utilizados nas linhas e seu comprimento, transformadores utilizados, capacitores, geradores e as cargas do sistema, era poss?vel calcular os valores das tens?es, correntes, dos fluxos de pot?ncia e das perdas do mesmo. Contudo, naquela ?poca, este tipo de c?lculo apresentava algumas limita??es como, em primeiro lugar, o m?todo utilizado para resolver o sistema de equa??es n?o lineares, Gauss-Siedel, fundamental para realiza??o do c?lculo de fluxo de carga, era bastante lento. E em segundo, os computadores da ?poca al?m de extremamente caros e raros eram grandes e lentos. No final da d?cada de 60, Domell apresenta em seu trabalho uma proposta de resolu??o de fluxo de carga baseado no m?todo Newton-Rhapson. A partir da?, o m?todo apresentado por Domell passou a se uma referencia na resolu??o de c?lculo de fluxo de carga. O m?todo de Newton (como passou a ser chamado), al?m de apresentar uma excelente converg?ncia para sistemas ditos mal comportados, ? bastante r?pido. Depois da apresenta??o do trabalho de Domell muitos outros trabalhos foram publicados baseados na sua formula??o, tentando melhorar ainda as caracter?sticas do m?todo. Pois, mesmo naquela ?poca, os computadores ainda apresentavam duas limita??es b?sicas, velocidade de processamento e a limita??o de mem?ria. Portanto, os m?todos baseados no de Newton tentavam diminuir a quantidade de c?lculos e o tamanho das matrizes utilizados no processo, tentado conservar a robustez do m?todo original. Uma caracter?stica comum entre os m?todos apresentados at? o final dos anos 80, era que eles eram desenvolvidos baseados nas caracter?sticas dos sistemas de transmiss?o de energia el?trica. Ou seja, at? ent?o, a distribui??o de energia era uma ?rea em que os engenheiros n?o se preocupavam. E para realiza??o de qualquer estudo para sistemas de distribui??o era utilizava-se os m?todos desenvolvidos para sistemas de transmiss?o. Por?m, nos anos 90, esta tend?ncia come?ou a mudar, em Janeiro de 1990 Cespedes apresenta um m?todo desenvolvido especialmente para sistemas radiais de distribui??o de energia el?trica. O m?todo apresentado por Cespedes explora a principal caracter?stica dos sistemas de distribui??o, a sua forma??o radial e, al?m disso, o m?todo n?o sugere na sua formula??o que o sistema tenha alto valor da rela??o entre a indut?ncia e a resist?ncia das linhas, como no m?todo de Newton. Com o passar dos anos, o aparecimento de novos tipos de cargas mais sens?veis a qualidade da energia, a regulamenta??o do fornecimento de energia com o aparecimento de novas leis, a competi??o entre as distribuidoras, a privatiza??o do fornecimento e a necessidade de redu??o dos custos em geral, os engenheiros passaram a ter uma outra preocupa??o: a qualidade e custo do fornecimento. Ou seja, o problema da resolu??o de c?lculos de fluxo de carga n?o seria mais o de tempo de processamento nem da quantidade de mem?ria envolvida, os engenheiros estariam agora preocupados com a fidelidade da representa??o matem?tica dos elementos do sistema e o desenvolvimento de t?cnicas de otimiza??o para a instala??o e dimensionamento dos elementos dos sistemas. Nos primeiros fluxos de carga as representa??es dos elementos eram bastante elementares, fazendo-se muitas aproxima??es. Inicialmente, todo o sistema era reduzido a um equivalente monof?sico, ou seja, as indut?ncias m?tuas das linhas eram desprezadas, as cargas eram consideradas perfeitamente equilibradas, teriam que ser necessariamente todas trif?sicas e o efeito da liga??o das bobinas entre o prim?rio e o secund?rio dos transformadores n?o era considerado. Estes tipos de aproxima??es limitavam muito o poder de an?lise dos engenheiros, pois a representa??o matem?tica era bem diferente da realidade encontrada no sistema real, dificultando an?lises mais precisas. Com o passar dos anos e o aumento da necessidade foram aparecendo fluxos de carga trif?sicos, com uma modelagem matem?tica mais fiel dos equipamentos, e com isso os resultados passaram a ser mais compat?veis com a realidade, possibilitando aos engenheiros an?lises mais precisas. O uso de t?cnicas de otimiza??o associado a c?lculos de fluxo de carga, permitiu que os resultados dos fluxos n?o somente apresentasse o estado do sistema, calculando-se unicamente os valores das vari?veis de interesse, para um carregamento qualquer. Agora, com esta nova ferramenta, os engenheiros poderiam fazer estudos verificando a localiza??o e dimensionamento ?timo de equipamentos no sistema. Domell, em um trabalho pioneiro, desenvolveu um m?todo de c?lculo defluxo de carga no qual eram calculados os reativos necess?rios que deveriam ser injetados em cada barra do sistema, de modo que as perdas do sistema fossem m?nimas. Em resumo, c?lculos de fluxo de carga ?timos permitem que, se escolhendo uma vari?vel de controle e uma fun??o objetivo, encontre-se um ponto onde o valor da fun??o objetivo seja ?timo quando for calculado para o valor encontrado da vari?vel de controle. A proposta desse trabalho ?, inicialmente, desenvolver um fluxo de carga trif?sico para sistemas radiais de distribui??o, baseado no m?todo de CESPEDES, cuja representa??o matem?tica dos elementos do sistema seja o mais fiel poss?vel ao seu funcionamento real. Este fluxo de carga servir? como base para, em uma segunda etapa, a aplica??o de t?cnicas de otimiza??o visando o dimensionamento ?timo de elementos do sistema. Para que se possa utilizar t?cnicas de otimiza??o, inicialmente, foram desenvolvidos m?todos para se encontrar como o sistema se comporta, sobre algum aspecto, quando o valor de uma vari?vel de controle ? modificado, ou seja, calcular o valor da derivada de uma fun??o com rela??o a uma vari?vel espec?fica. Em posse do c?lculo dessas derivadas, ser?o aplicadas t?cnicas de otimiza??o para se encontrar o ponto de ?timo